Porphyria: Complete Guide to Symptoms, Causes, and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Porphyria: Complete Guide to Symptoms, Causes, and Treatment
Content current as of the latest published medical reference (August 18, 2026).
TL;DR
Porphyria is a group of rare disorders caused by a buildup of natural chemicals called porphyrins, which are needed to make heme for hemoglobin. It is usually inherited, and a problem with any of the eight enzymes that make heme determines the type. Acute porphyrias affect the nervous system with rapid attacks of severe pain, red or brown urine, and mental changes; cutaneous porphyrias affect the skin after sun exposure. Although porphyria can't be cured, treatment includes hemin injections for acute attacks, phlebotomy and medication for skin forms, and careful avoidance of triggers.
Quick Answer
Porphyria refers to a group of rare disorders that result from a buildup of natural chemicals called porphyrins in the body. Porphyrins are needed to make heme, a part of hemoglobin — the protein in red blood cells that carries oxygen. Eight enzymes are needed to change porphyrins into heme, and without enough of any of these enzymes, porphyrins build up, mainly causing problems in the nervous system or skin. Acute porphyrias start rapidly and cause attacks of severe belly, chest, leg, or back pain, red or brown urine, and mental changes; acute intermittent porphyria (AIP) is the most common acute form. Cutaneous porphyrias cause sun-sensitive skin symptoms like burning pain, blisters, and fragile skin; porphyria cutanea tarda (PCT) is the most common porphyria of all, and erythropoietic protoporphyria (EPP) is the most common childhood porphyria. Porphyria is usually inherited, can't be cured, and is managed with medicines such as hemin or givosiran, blood draws (phlebotomy), and strict avoidance of triggers.
What Is Porphyria?
Porphyria (por-FEAR-e-uh) refers to a group of rare disorders that result from a buildup of natural chemicals called porphyrins in the body. Porphyrins are needed to make heme, a part of hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen to the body's organs and tissues.
Eight enzymes are needed to change porphyrins into heme. Without enough of any of these enzymes, porphyrins build up in the body. High levels of porphyrins can cause major problems, mainly in the nervous system and skin.
Answer nugget: Porphyria is a group of rare disorders caused by a buildup of porphyrins — natural chemicals needed to make heme for hemoglobin; eight enzymes perform this conversion, and a shortage of any one enzyme determines the type of porphyria.
Heme is made in the bone marrow and liver. In cutaneous porphyrias, porphyrins build up in the skin, and when exposed to sunlight they cause symptoms. In acute porphyrias, the buildup affects the nervous system, causing symptoms.
Porphyria is usually inherited — one or both parents pass along a changed gene to their child. Although porphyria can't be cured, medicines and certain lifestyle changes may help you manage it.
The Two Main Types of Porphyria
There are two general types of porphyrias. Acute porphyrias start rapidly and mainly affect the nervous system. Cutaneous porphyrias mainly affect the skin. A few types of porphyrias affect both the nervous system and the skin.
| Type | What It Affects | How It Starts | Most Common Form | |---|---|---|---| | Acute porphyrias | Mainly the nervous system | Rapidly; symptoms may last hours, days, or weeks | Acute intermittent porphyria (AIP) | | Cutaneous porphyrias | Mainly the skin | After exposure to sunlight or sometimes artificial light | Porphyria cutanea tarda (PCT) — the most common of all porphyrias |
Answer nugget: The two main types of porphyria are acute porphyrias, which start rapidly and mainly affect the nervous system, and cutaneous porphyrias, which mainly affect the skin after sun exposure; porphyria cutanea tarda (PCT) is the most common porphyria of all.
What Are the Symptoms of Acute Porphyria?
Symptoms appear quickly and can be severe, lasting hours, days, or weeks. The most common form of acute porphyria is called acute intermittent porphyria (AIP). AIP may last hours or days, and "intermittent" means the symptoms may go away but return later. When symptoms occur, they are sometimes called attacks.
Symptoms of acute porphyrias may include:
| Symptom | Description | |---|---| | Severe pain | Pain in the belly, chest, legs, or back | | Digestive problems | Constipation, nausea, and vomiting | | Nerve and muscle problems | Muscle pain, tingling, numbness, weakness, or paralysis | | Urine changes | Red or brown urine | | Mental changes | Anxiety, hallucinations, or mental confusion | | Heart problems | Rapid or irregular heartbeats you can feel, called palpitations | | Breathing problems | Difficulty breathing during an attack | | Blood pressure | High blood pressure | | Seizures | Convulsions that require urgent treatment |
Answer nugget: Symptoms of acute porphyria attacks include severe belly, chest, leg, or back pain; digestive problems; muscle pain, tingling, numbness, weakness, or paralysis; red or brown urine; anxiety, hallucinations, or confusion; palpitations; breathing problems; high blood pressure; and seizures.
What Are the Symptoms of Cutaneous Porphyria?
Cutaneous porphyrias cause skin symptoms as a result of sensitivity to sunlight and usually don't affect the nervous system. Sun exposure may cause sensitivity to the sun and sometimes artificial light, causing burning pain in the skin.
Other sun-related symptoms include sudden painful skin redness and swelling, blisters on exposed skin (usually the hands, arms, and face), fragile thin skin with changes in skin color, itching, and too much hair growth in affected areas. Red or brown urine can also occur.
Answer nugget: Symptoms of cutaneous porphyria after sun exposure include burning pain in the skin, sudden redness and swelling, blisters on the hands, arms, and face, fragile thin skin, itching, and excess hair growth in affected areas.
Erythropoietic protoporphyria (EPP) is a rare type of cutaneous porphyria and the most common childhood porphyria. Sun or artificial light exposure quickly results in painful skin burning, irritation, and swelling. Small bumps and blisters also appear, and repeated exposures can cause thick, leathery skin and scarring.
What Causes Porphyria?
All types of porphyria involve a problem making heme. A shortage or change in any of the eight enzymes that turn porphyrins into heme causes a buildup of porphyrins. Which enzyme is affected determines the type of porphyria.
Answer nugget: Porphyria is caused by a shortage or change in one of the eight enzymes that convert porphyrins into heme; which enzyme is affected determines the type of porphyria, and the condition is usually inherited through one or both parents.
Is Porphyria Inherited?
Most forms of porphyria are caused by a gene change passed down from one or both parents. The inheritance can follow one of two patterns:
| Inheritance Pattern | How It Works | Chance of Passing It On | |---|---|---| | Autosomal dominant | A changed gene from one of your parents; only one changed gene is needed to be affected | 50% chance of having an affected child with each pregnancy | | Autosomal recessive | Changed genes from both parents are needed to be affected | 25% chance of having an affected child when both parents are carriers |
Just because you inherit a gene or genes that can cause porphyria doesn't mean that you'll have symptoms. You might never have symptoms, and this is the case for most carriers of the changed genes.
What Causes Porphyria Cutanea Tarda?
Porphyria cutanea tarda (PCT) usually is not passed down in families. In PCT, certain triggers can cause a buildup of porphyrins that may cause symptoms. Examples of triggers include too much iron in the body (often due to hemochromatosis), viral infections such as HIV or hepatitis C, heavy alcohol use, smoking, and hormone changes during the menstrual period.
What Triggers a Porphyria Attack?
In addition to genetic risk factors, environmental risk factors may trigger symptoms in porphyria. When exposed to the trigger, the body's demand for heme production increases. This overwhelms the low level of a needed enzyme, setting in motion a process that causes a buildup of porphyrins.
| Trigger | How It Provokes an Attack | |---|---| | Exposure to sunlight | Raises porphyrins in the skin in cutaneous forms | | Certain medicines | Birth control pills, sedatives, and barbiturates can trigger acute attacks | | Recreational or illicit drugs | Can set off acute attacks | | Dieting or fasting | Increases the body's demand for heme production | | Smoking | Linked to PCT and can trigger symptoms | | Physical stress | Infections, other illnesses, or surgery raise heme demand | | Emotional stress | Can provoke acute attacks | | Alcohol use | A known trigger, especially for PCT | | Hormone changes | Hormone changes during the menstrual period can trigger attacks |
What Are the Complications?
Possible complications depend on the form of porphyria.
Acute porphyrias can be life-threatening if an attack isn't promptly treated. During an attack, you may experience dehydration from loss of fluids, breathing problems, seizures, or high blood pressure, and you may need a hospital stay. Long-term complications with repeat acute attacks may include long-term pain, chronic kidney failure, liver damage, or liver cancer.
Cutaneous porphyrias can result in permanent skin damage. The skin blisters can become infected, and healed skin may have a changed appearance and coloring, be fragile and slow to heal, or leave scars. Cutaneous porphyrias also increase the risk of liver damage or liver cancer.
In rare cases, a bone marrow transplant or liver transplant may be needed.
When Should You See a Doctor?
Many symptoms of porphyria are like those of other, more common conditions, which can make it difficult to know if you're having an attack. If you have symptoms that could be porphyria, get medical attention. Prompt treatment is important, since acute attacks can be life-threatening if they aren't treated quickly.
Answer nugget: Because porphyria symptoms mimic common conditions, get medical attention if you experience sudden unexplained severe belly pain with red or brown urine, or burning skin pain and blisters after brief sun exposure.
How Is Porphyria Diagnosed?
Because porphyria is rare and its symptoms resemble more common diseases, it can be difficult to diagnose. Lab tests are needed to make a diagnosis and to determine which form of the condition you have.
The types of tests depend on the type of porphyria your health care provider suspects. Tests include a combination of blood, urine, or stool testing to measure porphyrin levels, and other tests may be needed. Genetic tests may be helpful to confirm the diagnosis and determine the type of porphyria you have.
Talking with a genetic counselor can give you information about genetic tests and the risk of porphyria for your children. If you have porphyria, genetic testing and counseling may also be recommended for family members.
How Is Porphyria Treated?
Treatment depends on the type of porphyria you have and how severe your symptoms are. Treatment includes medicine, identifying and avoiding symptom triggers, and relieving symptoms when they occur.
Avoiding Triggers
Avoiding triggers is the first line of defense. Don't use medicines known to trigger acute attacks — ask your health care provider for a list of safe and unsafe medicines, including herbal supplements and over-the-counter products. Don't use recreational or illicit drugs and avoid heavy drinking.
Avoid fasting and dieting that involves severe calorie restriction, and don't smoke. Minimize sun exposure: when outdoors, wear protective clothing and use an opaque blocking sunscreen, such as one with zinc oxide or titanium dioxide. Use an SPF of at least 30 for short or limited sun exposure and an SPF of 50 for longer times outdoors. When indoors, use window filters.
Treat infections and other illnesses promptly, take steps to reduce emotional stress, and talk to your health care provider about options to prevent premenstrual attacks.
Treating Acute Porphyria Attacks
Treatment of acute porphyria attacks focuses on providing fast treatment of symptoms and preventing complications. Treatment may include injections of hemin, a medicine that is a form of heme, to limit your body's production of porphyrins.
You may also receive fluid that contains glucose (sugar) through a vein, or sugar taken by mouth if able, to make sure you get enough carbohydrates. A hospital stay may be needed for treatment of symptoms such as severe pain, vomiting, dehydration, or breathing problems.
Answer nugget: Acute porphyria attacks are treated with hemin injections that limit the body's production of porphyrins, IV glucose to ensure adequate carbohydrates, and hospital care for severe pain, vomiting, dehydration, or breathing problems.
Givosiran is a monthly shot for adults with acute hepatic porphyria. In hepatic porphyrias, which include acute intermittent porphyria, the lack of the enzymes needed to make heme occurs in the liver. Givosiran can reduce the number of porphyria attacks. Discuss safety information and potential serious side effects with your health care provider.
Treating Cutaneous Porphyrias
Treatment of cutaneous porphyrias focuses on reducing exposure to triggers such as sunlight and reducing the amount of porphyrins in the body to relieve symptoms. Reducing porphyrins may include:
| Option | How It Works | Who It's For | |---|---|---| | Phlebotomy | Regularly scheduled blood draws to reduce iron in the body, which decreases porphyrins | People who can tolerate blood draws | | Hydroxychloroquine | A malaria medicine that helps absorb excess porphyrins and helps the body excrete them more quickly | People who can't tolerate phlebotomy | | Vitamin D supplement | Replaces low vitamin D levels caused by avoiding sunlight | Anyone limiting sun exposure |
High doses of beta carotene are a common treatment for erythropoietic protoporphyria. A treatment option approved only for erythropoietic protoporphyria is afamelanotide, a medicine that increases melanin in the skin. This protects skin from sunlight and allows more time in the sun without a painful skin reaction. An implant is placed under the skin that slowly releases the medicine.
Living with Porphyria: Three Essential Habits
If you have porphyria, three habits make day-to-day management much safer.
First, learn what could trigger symptoms. Talk to your health care provider about the type of porphyria you have, and learn about possible symptom triggers and how to avoid them.
Second, inform your health care providers. Tell all your providers that you have porphyria, because sometimes treatments, medicines, illness, or surgery can trigger porphyria symptoms.
Third, wear a medical alert bracelet or necklace. Have information about your condition placed on a medical alert bracelet or necklace, and always wear it.
Preparing for Your Appointment
If you have symptoms of porphyria, you'll likely start by seeing your primary care provider. Because porphyria can be difficult to diagnose, you may be referred to a specialist in blood disorders (hematologist) or skin conditions (dermatologist).
Before your appointment, make a list of any symptoms you're experiencing, including those that may seem unrelated. Bring photos of any rashes in case you don't have one on the day. Share key personal information, including major stresses, recent life changes, previous symptoms, and what may have triggered them. List all medicines, vitamins, herbs, and supplements you take, including doses, and bring your questions.
Your provider will likely ask when your symptoms started, whether they are constant or come and go, what makes them better or worse, and whether any family members have similar symptoms.
Conclusion: A Manageable Rare Disease — If You Know Your Triggers
Porphyria sits in an unusual corner of medicine: a rare, inherited disorder that shows up as something entirely ordinary — belly pain, sunburn-like skin, anxiety, or discolored urine. That camouflage is exactly why it takes so long to diagnose, and why knowing your own risk factors matters.
The good news is that porphyria follows rules. If you know which form you have, which eight-enzyme step failed, and which triggers provoke it, you can prevent most attacks. Hemin injections, monthly givosiran shots, scheduled phlebotomy, and sun-protection strategies turn a frightening condition into a manageable one. And because attacks can be life-threatening, the single most important action is simple: get medical attention promptly when symptoms strike, wear your medical alert bracelet, and make sure every provider you see knows your diagnosis.
Next step: If you've had sudden severe pain with red or brown urine, or painful burning skin after brief sun exposure, talk to your health care provider — and if porphyria runs in your family, ask about genetic testing and counseling for yourself and your relatives.
Frequently Asked Questions
What is porphyria?
Porphyria refers to a group of rare disorders that result from a buildup of natural chemicals called porphyrins in the body. Porphyrins are needed to make heme, a part of hemoglobin — the protein in red blood cells that carries oxygen. Eight enzymes are needed to change porphyrins into heme; a shortage or change in any of them causes a buildup.
What are the two types of porphyria?
There are two general types. Acute porphyrias start rapidly and mainly affect the nervous system. Cutaneous porphyrias mainly affect the skin, and a few types affect both the nervous system and the skin.
What triggers a porphyria attack?
Triggers include sunlight, certain medicines (such as birth control pills, sedatives, and barbiturates), recreational or illicit drugs, dieting or fasting, smoking, physical stress (infections, illness, surgery), emotional stress, alcohol use, and hormone changes during the menstrual period. Triggers increase the body's demand for heme, overwhelming a low enzyme level and building up porphyrins.
Can porphyria be cured?
No. Although porphyria can't be cured, medicines and certain lifestyle changes may help you manage it. Treatment depends on the type of porphyria you have.
How are acute porphyria attacks treated?
Acute attacks are treated with injections of hemin (a form of heme) to limit the body's production of porphyrins, intravenous glucose to ensure enough carbohydrates, and hospital care for severe pain, vomiting, dehydration, or breathing problems. Givosiran, a monthly shot, can reduce attacks in adults with acute hepatic porphyria.
How are cutaneous porphyrias treated?
Treatment focuses on reducing sun exposure and reducing porphyrins in the body. Options include phlebotomy (regular blood draws that lower iron and porphyrins), hydroxychloroquine for those who can't tolerate phlebotomy, vitamin D supplementation, high-dose beta carotene for EPP, and an afamelanotide skin implant approved only for erythropoietic protoporphyria.
Is porphyria inherited?
Most forms of porphyria are caused by a gene change passed down from one or both parents, following either an autosomal dominant pattern (one changed gene) or an autosomal recessive pattern (changed genes from both parents). However, inheriting a gene that can cause porphyria doesn't mean you'll have symptoms — many carriers never do.
Who should get genetic testing for porphyria?
If you have porphyria, genetic testing and counseling may be recommended for your family members. Siblings and other relatives may want testing to determine if they have the condition, and a genetic counselor can explain results and the risk to your children.
References
This article is for general educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment decisions.
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